The cross section for capture of a neutrino in mass state \(i\)  on tritium is [1]}
\(\sigma ^h_i(p,p_e)&&\\ && \hspace{-48.0pt}=\frac{G_F^2}{2\pi v_i} |V_{ud}|^2|U_{ei}|^2 F(Z,E_e)\frac{m_{^3 \rm He}}{m_{^3\rm H}}E_e p_e A^h_i (\bar{f}^2+3 \bar{g}^2), \nonumber \) 
